Gary Turner – BMC
Abstract
As IMS environments continue to grow in data volume, application complexity, and operational demands, many organizations are approaching the long standing 4GB and 8GB storage boundaries inherent to IMS control regions, dependent regions, and key IMS components. Crossing these thresholds can introduce performance degradation, unpredictable failures, or outages—making it essential for IMS teams to understand the architectural constraints, early warning indicators, and modernization strategies available.
This session provides a clear and practical overview of how IMS storage is structured, where
the 4GB and 8GB limits originate, and why they continue to matter even in modern z/OS
environments. Real world examples will illustrate how these limits surface operationally,
methods for resolving limitations, and the risks associated with ignoring them.